Constraints on the environment and energetics of the Broad-Line Ic SN2014ad from deep radio and X-ray observations

Broad-line type Ic Supernovae (BL-Ic SNe) are characterized by high ejecta velocity ($\gtrsim 10^4$ km s$^{-1}$) and are sometimes associated with the relativistic jets typical of long duration ($\gtrsim 2$ s) Gamma-Ray Bursts (L-GRBs). The reason why a small fraction of BL-Ic SNe harbor relativistic jets is not known. Here we present deep X-ray and radio observations of the BL-Ic SN2014ad extending from $13$ to $930$ days post explosion. SN2014ad was not detected at either frequency and has no observational evidence of a GRB counterpart. The proximity of SN2014ad ($d\sim 26$ Mpc) enables very deep constraints on the progenitor mass-loss rate $\dot{M}$ and on the total energy of the fast ejecta $E$. We consider two synchrotron emission scenarios for a wind-like circumstellar medium (CSM): (i) uncollimated non-relativistic ejecta, and (ii) off-axis relativistic jet. Within the first scenario our observations are consistent with GRB-less BL-Ic SNe characterized by a modest energy budget of their fast ejecta ($E \lesssim 10^{45}$ erg), like SNe 2002ap and 2010ay. For jetted explosions, we cannot rule out a GRB with $E \lesssim 10^{51}$ erg (beam-corrected) with a narrow opening angle ($\theta_j \sim 5^{\circ}$) observed moderately off-axis ($\theta_{\rm obs} \gtrsim 30^{\circ}$) and expanding in a very low CSM density ($\dot{M}$ $\lesssim 10^{-6}$ M$_{\odot}$ yr$^{-1}$). Our study shows that off-axis low-energy jets expanding in a low-density medium cannot be ruled out even in the most nearby BL-Ic SNe with extensive deep observations, and might be a common feature of BL-Ic SNe.Comment: 9 pages, 5 figures, accepted in Ap

Transplanted hepatocytes: Wiped out or washed out?

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IMAGE: A New Tool for the Prediction of Transcription Factor Binding Sites

IMAGE is an application tool, based on the vector quantization method, aiding the discovery of nucleotidic sequences corresponding to Transcription Factor binding sites. Starting from the knowledge of regulation regions of a number of co-expressed genes, the software is able to predict the occurrence of specific motifs of different lengths (starting from 6 base pairs) with a defined number of punctual mutations

PINK1 homozygous W437X mutation in a patient with apparent dominant transmission of parkinsonism.

We analyzed the PINK1 gene in 58 patients with early-onset Parkinsonism and detected the homozygous mutation W437X in 1 patient. The clinical phenotype was characterized by early onset (22 years of age), good re- sponse to levodopa, early fluctuations and dyskinesias, and psychiatric symptoms. The mother, heterozygote for W437X mutation, was affected by Parkinson’s disease and 3 further relatives were reported affected, according to an autosomal dominant transmission

Implicit iterative particle shifting for meshless numerical schemes using kernel basis functions

A novel particle shifting technique (PST) for meshless numerical methods is presented. The proposed methodology uses an implicit iterative particle shifting (IIPS) technique aiming to reduce the spatial particle’ anisotropy, which is associated with the discretization error in meshless numerical schemes based on kernel basis functions. The algorithm controls the particle spatial distribution through an implicit minimization problem, related to the particle concentration gradient and therefore, to the particles’ anisotropy. This results in accurate particle distributions, to demonstrate the effectiveness of the proposed method, the IIPS algorithm is tested within a smoothed particle hydrodynamics (SPH) framework, with static and kinematic cases, by examining the particle distributions and the corresponding spatial accuracy. Further, the computational cost of the proposed methodology is reported and it is shown that it introduces minimal overhead. Moreover, the simulations of the Taylor–Green vortex (TGV), employing a weakly-compressible SPH Navier–Stokes solver, confirmed the superior accuracy of the IIPS in comparison to existing explicit shifting approaches, in simulating internal flows

Differential response to hepatic differentiation stimuli of amniotic epithelial cells isolated from four regions of the amniotic membrane

Human Amniotic Epithelial Cells (hAEC) isolated from term placenta are a promising source for regenerative medicine. However, it has long been debated whether the hAEC population consists of heterogeneous or homogeneous cells. In a previous study, we investigated the characteristics of hAEC isolated from four different regions of the amniotic membrane finding significant heterogeneity. The aim of this study was to evaluate the hepatic differentiation capability of hAEC isolated from these four regions. Human term placentae were collected after caesarean section and hAEC were isolated from four regions of the amniotic membrane (R1-R4, according to their relative distance from the umbilical cord) and treated in hepatic differentiation conditions for 14 days. hAEC-derived hepatocyte-like cells showed marked differences in the expression of hepatic markers: R4 showed higher levels of Albumin and Hepatocyte Nuclear Factor (HNF) 4α whereas R1 expressed higher Cytochrome P450 enzymes, both at the gene and protein level. These preliminary results suggest that hAEC isolated from R1 and R4 of the amniotic membrane are more prone to hepatic differentiation. Therefore, the use of hAEC from a specific region of the amniotic membrane should be taken into consideration as it could have an impact on the outcome of therapeutic applications

Correlated electron-hole plasma in organometal perovskites

Organic-inorganic perovskites are a class of solution-processed semiconductors holding promise for the realization of low-cost efficient solar cells and on-chip lasers. Despite the recent attention they have attracted, fundamental aspects of the photophysics underlying device operation still remain elusive. Here we use photoluminescence and transmission spectroscopy to show that photoexcitations give rise to a conducting plasma of unbound but Coulomb-correlated electron-hole pairs at all excitations of interest for light-energy conversion and stimulated optical amplification. The conductive nature of the photoexcited plasma has crucial consequences for perovskite-based devices: in solar cells, it ensures efficient charge separation and ambipolar transport while, concerning lasing, it provides a low threshold for light amplification and justifies a favourable outlook for the demonstration of an electrically driven laser. We find a significant trap density, whose cross-section for carrier capture is however low, yielding a minor impact on device performance

Imaging of SNR IC443 and W44 with the Sardinia Radio Telescope at 1.5 GHz and 7 GHz

Observations of supernova remnants (SNRs) are a powerful tool for investigating the later stages of stellar evolution, the properties of the ambient interstellar medium, and the physics of particle acceleration and shocks. For a fraction of SNRs, multi-wavelength coverage from radio to ultra high-energies has been provided, constraining their contributions to the production of Galactic cosmic rays. Although radio emission is the most common identifier of SNRs and a prime probe for refining models, high-resolution images at frequencies above 5 GHz are surprisingly lacking, even for bright and well-known SNRs such as IC443 and W44. In the frameworks of the Astronomical Validation and Early Science Program with the 64-m single-dish Sardinia Radio Telescope, we provided, for the first time, single-dish deep imaging at 7 GHz of the IC443 and W44 complexes coupled with spatially-resolved spectra in the 1.5-7 GHz frequency range. Our images were obtained through on-the-fly mapping techniques, providing antenna beam oversampling and resulting in accurate continuum flux density measurements. The integrated flux densities associated with IC443 are S_1.5GHz = 134 +/- 4 Jy and S_7GHz = 67 +/- 3 Jy. For W44, we measured total flux densities of S_1.5GHz = 214 +/- 6 Jy and S_7GHz = 94 +/- 4 Jy. Spectral index maps provide evidence of a wide physical parameter scatter among different SNR regions: a flat spectrum is observed from the brightest SNR regions at the shock, while steeper spectral indices (up to 0.7) are observed in fainter cooling regions, disentangling in this way different populations and spectra of radio/gamma-ray-emitting electrons in these SNRs.Comment: 13 pages, 9 figures, accepted for publication to MNRAS on 18 May 201

Modular versus monoblock stem in revision total hip arthroplasty: a systematic review and meta-analysis

Background: Total hip arthroplasty (THA) is estimated to grow in the following decades with a consequent increase of THA revisions (rTHA). This systematic review and meta-analysis aims to compare modular and monoblock stem in rTHA surgery, focusing on clinical and radiological outcomes and complication rates. Methods: A literature search was performed using the following search strategy: ((Modular stem) OR (monolithic stem)) AND (hip review) on PubMed, Scopus, and Cochrane. Randomized controlled trials (RCTs) and observational studies (OS) compared clinical and radiological outcomes, and complication rates for monoblock and modular revision femoral stem were included. The risk of bias was assessed through the Methodological Index for Non-Randomized Studies (MINORS) score. The Review Manager (RevMan) software was used for the meta-analysis. The rate of complications was assessed using odds ratio (OR) with 95% confidence intervals (CIs). Results: The authors included 11 OS and one RCT with 3,671 participants (mean age: 68.4 years old). The mean follow-up was 46.9 months. There was no prevalence of subsidence for one type of stem. Mean subsidence was from 0.92 to 10 mm for modular stem and from 1 to 15 mm for monoblock stem. Postoperative Harris Hip Score (HHS) showed better results with modular stems without statistical significance [mean difference (MD) =1.32; 95% CI: −1.62 to 4.27; P=0.38]. No statistically significant difference was found for dislocations (OR =2.48; 95% CI: 0.67 to 9.14; P=0.17), infections (OR =1.07; 95% CI: 0.51 to 2.23; P=0.86), intraoperative fractures (OR =1.62; 95% CI: 0.42 to 6.21; P=0.48), and postoperative fractures (OR =1.60; 95% CI: 0.55 to 4.64; P=0.39). Conclusions: Modular and monoblock stems show comparable and satisfactory clinical and radiological outcomes for rTHA. Both stems are valid and effective options for managing femoral bone deficit in hip revision surgery. The main limitation of this study is the small number and low quality of enclosed studies that compared the two stems. Moreover, the modular stem is usually used for more complex cases with lower quality femoral bone stock